feat: gardener prioritizes blocker issues that starve the factory

Adds PRIORITY_blockers_starving_factory detection: scans backlog issues'
deps, finds any that are open but not labeled backlog, and puts them
at the top of the Claude prompt as highest priority for promotion.

Previously, gardener promoted random tech-debt issues while the actual
blockers (e.g. #650, #563, #714, #743) were ignored, leaving all
backlog items permanently stuck.

gardener/gardener-poll.sh

@@ -138,7 +138,43 @@ while IFS=$'\t' read -r num body; do
   done
 done < <(echo "$ISSUES_JSON" | jq -r '.[] | "\(.number)\t\(.body // "")"' | head -20)
 
-# 5. Tech-debt issues needing promotion to backlog (primary mission)
+# 5. Blocker detection: find issues blocking backlog items that aren't themselves backlog
+# This is the HIGHEST PRIORITY — a non-backlog blocker starves the entire factory
+BACKLOG_ISSUES=$(echo "$ISSUES_JSON" | jq -r '.[] | select(.labels | map(.name) | index("backlog")) | .number')
+BLOCKER_NUMS=""
+for BNUM in $BACKLOG_ISSUES; do
+  BBODY=$(echo "$ISSUES_JSON" | jq -r --arg n "$BNUM" '.[] | select(.number == ($n | tonumber)) | .body // ""')
+  # Extract deps from ## Dependencies / ## Depends on / ## Blocked by
+  IN_SECTION=false
+  while IFS= read -r line; do
+    if echo "$line" | grep -qiP '^##?\s*(Dependencies|Depends on|Blocked by)'; then IN_SECTION=true; continue; fi
+    if echo "$line" | grep -qP '^##?\s' && [ "$IN_SECTION" = true ]; then IN_SECTION=false; fi
+    if [ "$IN_SECTION" = true ]; then
+      for dep in $(echo "$line" | grep -oP '#\d+' | grep -oP '\d+'); do
+        [ "$dep" = "$BNUM" ] && continue
+        # Check if dep is open but NOT backlog-labeled
+        DEP_STATE=$(echo "$ISSUES_JSON" | jq -r --arg n "$dep" '.[] | select(.number == ($n | tonumber)) | .state' 2>/dev/null || true)
+        DEP_LABELS=$(echo "$ISSUES_JSON" | jq -r --arg n "$dep" '.[] | select(.number == ($n | tonumber)) | [.labels[].name] | join(",")' 2>/dev/null || true)
+        if [ "$DEP_STATE" = "open" ] && ! echo ",$DEP_LABELS," | grep -q ',backlog,'; then
+          BLOCKER_NUMS="${BLOCKER_NUMS} ${dep}"
+        fi
+      done
+    fi
+  done <<< "$BBODY"
+done
+# Deduplicate blockers
+BLOCKER_NUMS=$(echo "$BLOCKER_NUMS" | tr ' ' '\n' | sort -un | head -10)
+if [ -n "$BLOCKER_NUMS" ]; then
+  BLOCKER_LIST=""
+  for bnum in $BLOCKER_NUMS; do
+    BTITLE=$(echo "$ISSUES_JSON" | jq -r --arg n "$bnum" '.[] | select(.number == ($n | tonumber)) | .title' 2>/dev/null || true)
+    BLABELS=$(echo "$ISSUES_JSON" | jq -r --arg n "$bnum" '.[] | select(.number == ($n | tonumber)) | [.labels[].name] | join(",")' 2>/dev/null || true)
+    BLOCKER_LIST="${BLOCKER_LIST}#${bnum} [${BLABELS:-unlabeled}] ${BTITLE}\n"
+  done
+  PROBLEMS="${PROBLEMS}PRIORITY_blockers_starving_factory: these issues block backlog items but are NOT labeled backlog — promote them FIRST:\n${BLOCKER_LIST}\n"
+fi
+
+# 6. Tech-debt issues needing promotion to backlog (secondary to blockers)
 TECH_DEBT_ISSUES=$(echo "$ISSUES_JSON" | jq -r '.[] | select(.labels | map(.name) | index("tech-debt")) | "#\(.number) \(.title)"' | head -10)
 if [ -n "$TECH_DEBT_ISSUES" ]; then
   TECH_DEBT_COUNT=$(echo "$TECH_DEBT_ISSUES" | wc -l)
@@ -179,8 +215,11 @@ $(echo -e "$PROBLEMS")
 - NEVER echo, log, or include the actual token value in any output — always reference \$CODEBERG_TOKEN
 - You're running in the project repo root. Read README.md and any docs/ files before making decisions.
 
-## Primary mission: promote tech-debt → backlog
+## Primary mission: unblock the factory
-Most open issues are raw review-bot findings labeled \`tech-debt\`. Your main job is to convert them into well-structured \`backlog\` items the dev-agent can execute. For each tech-debt issue:
+Issues prefixed with PRIORITY_blockers_starving_factory are your TOP priority. These are non-backlog issues that block existing backlog items — the dev-agent is completely starved until these are promoted. Process ALL of them before touching regular tech-debt.
+
+## Secondary mission: promote tech-debt → backlog
+Most open issues are raw review-bot findings labeled \`tech-debt\`. Convert them into well-structured \`backlog\` items the dev-agent can execute. For each tech-debt issue:
 1. Read the issue body + referenced source files to understand the real problem
 2. Check AGENTS.md (and sub-directory AGENTS.md files) for architecture context
 3. Add missing sections: \`## Affected files\`, \`## Acceptance criteria\` (checkboxes, max 5), \`## Dependencies\`